Generally, nitroalkanes are useful as solvents, reactants and reaction intermediates in various industries including coatings, paints, inks, adhesives, polymers, resins, etc. For example, nitroalkanes are used as feedstocks to prepare nitroalcohols which can be further reduced to aminoalcohols. In particular, nitromethane (CH3NO2) is a highly polar liquid often used as a solvent, such as an extraction solvent, a reaction medium, or a cleaning solvent. It is also a reaction intermediate for the production of pharmaceuticals, pesticides, explosives, fibers, and coatings. Another valuable nitroalkane, for example, is 2-nitropropane (CH3CHNO2CH3) which is a colorless liquid commonly used as a solvent, chemical intermediate, or starting material to produce other industrially useful compounds. As a solvent, 2-nitropropane is slightly soluble in water and miscible in numerous solvents including most aromatic hydrocarbons, ketones, esthers, and ethers. Thus, it is useful for making inks, paints, adhesives, varnishes, polymers, resins, and coatings. 2-nitropropane is also used in explosives and as a gasoline additive.
Nitroalkanes are produced industrially by contacting propane with nitric acid at high temperatures, such as 350-450° C., which results in a mixed product containing: nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane.
A different process for preparing nitroalkanes is described in U.S. Pat. No. 4,319,059. In this process, an alpha-bromoalkanoic acid is first reacted with an alkali metal nitrite, in the presence of a magnesium ion (Mg2+), in an aprotic solvent to form a chelate, which is neutralized with a mineral acid to produce a nitroalkane having one less carbon atom than the reactant bromoalkanoic acid.
No known processes for preparing nitroalkanes by dehydroxylating the corresponding nitroalcohols are known.
Reductive dehydroxylation is known for activated alcohols, e.g., benzylic alcohols. It has not been documented for nitroalcohols such as the 1,2-nitroalcohols.
The ability to produce nitroalkanes from alternative feedstocks, such as, nitroalcohols or nitropolyols, is desirable.